Conventionally, in a storage apparatus, data input/output (I/O) processing relative to a data I/O request from a host computer is carried out by a processor corresponding to the port connected to this host computer. For this reason, data I/O processing of high-priority jobs and low-priority jobs may be carried out by the same processor. In a situation like this, when the low-priority job load is great, the affects of this load can make it impossible to ensure bandwidth for high-priority jobs.
A method for solving this problem has been proposed (refer to Japanese Patent Laid-open No. 2002-108567) whereby a user configures in a single storage apparatus either an upper limit or threshold for a data I/O process, which treats either a port, WWN (World Wide Name) or device as a unit, and suppresses data I/O for non-priority jobs, thereby ensuring bandwidth for the I/O of data for priority jobs.
However, in the method disclosed in Japanese Patent Laid-open No. 2002-108567, only I/O of non-priority data is suppressed. Therefore, when there is a plurality of high-priority data, since the respective high-priority data will be handled uniformly, the input/output of one high-priority data will prevent the input/output of other high-priority data.
Further, since the method disclosed in Japanese Patent Laid-open No. 2002-108567 configures an upper limit, which treats a port, WWN or device as a unit, for example, when a port is treated as the unit and an upper limit is configured, it is not possible to adjust I/O processing among a plurality of jobs utilizing the same port. That is, when the same port is being used, it is not possible to give precedence to I/O processing of a high-priority job even when there are jobs with different priorities.